Topical Preparations Exam Notes PDF

**Rheology, Viscosity, Newtonian/Non-Newtonian Systems and Thixotropy** 1. Define rheology, viscosity and fluidity. Explain the difference between shear rate and shear stress. 2. Define Newtonian and non-Newtonian fluid behaviors. Define each of the 3 types of non-Newtonian systems and d...

**Rheology, Viscosity, Newtonian/Non-Newtonian Systems and Thixotropy** 1. Define rheology, viscosity and fluidity. Explain the difference between shear rate and shear stress. 2. Define Newtonian and non-Newtonian fluid behaviors. Define each of the 3 types of non-Newtonian systems and distinguish them from each other. Identify the general types of liquids and liquid or semisolid dosage forms that belong to each category. 3. Explain why flocculated particles in concentrated suspensions exhibit plastic flow. 4. Explain why polymers in solution exhibit pseudoplastic flow. 5. Explain how processing dilatant materials can lead to equipment damage. 6. Define thixotropy and describe situations in which it would be useful in pharmacy. - 1. Describe the difference between a topical and a transdermal dermatological product. 2. Define: - - Emollients - Humectants - Stiffening agents - Protectants - Rubefacients - Counterirritants - Antioxidants - Penetration enhancers - Ointments - Creams - Pastes - Plasters - Glycerogelatins - Gels - Lotions - Liniments - Collodions - Topical powders - Sticks 3. 4. List the categories of ointment bases and describe the general properties of each type. Know which contain oleaginous components and which do not. 5. Determine which bases allow for incorporation of aqueous material (including relative capacities). 6. Describe situations in which levigating agents are unnecessary. 7. Identify which levigating agents are compatible with which category of ointment bases. 8. Explain why *Pseudomonas aeruginosa* and *Staphylococcus aureus* are of particular concern with topical preparations. 9. Explain why extra paraben or benzoic acid might be needed when preserving some topical formulations. 10. Identify an appropriate type of semisolid to apply to moist, weeping lesions and explain your reasoning for this choice. 11. Identify an appropriate type of semisolid to apply to dry, scaly lesions and explain your reasoning for this choice. 12. Differentiate between hydrogels and organogels. 13. Explain why the thermoreversible nature of poloxymer gels can be advantageous. 14. Explain how carbomers gel. 15. Explain why liniments should not be applied to bruised skin. 16. Explain the function of camphor and castor oil in collodion formulations.